Abstract 288: Nocturnal Blood Pressure Elevation or Abnormal Circadian Pattern. Which is Better Associated with Cardiovascular Risk?

Background and aim: A blunted decrease in nighttime BP with respect to daytime values (the non-dipping pattern) and an absolute increase in nocturnal BP have both been related to a worse cardiovascular prognosis. However, these are not independent variables and little is know about which is better related with cardiovascular risk. The aim of the study was to compare clinical data in untreated hypertensives classified on the basis of both absolute nocturnal BP and the dipping pattern. Methods: We included 37096 untreated patients from the Spanish ABPM Registry. They were classified in 4 different groups: Group 1: 15743 (42%) with mean nocturnal systolic BP (NSBP) < 120 mmHg and nocturnal systolic dip (NSD) ≥ 10%; Group 2: 6166 (17%) patients with NSBP < 120 mmHg and NSD < 10%; Group 3: 4847 (13%) patients with NSBP ≥ 120 mmHg and NSD ≥ 10%; and Group 4: 10340 (28%) patients with NSBP ≥ 120 mmHg and NSD < 10%. Groups were compared by ANOVA, Kruskal-Wallis or Chi square statistics (p for trend), with specific comparisons between groups 2 and 3 (Bonferroni corrected t-test, Mann Whitney or Chi square statistics). Results: Compared to patients with elevated NSBP but normal NSD, those with abnormal NSD but normal NSBP were more frequently women, diabetics, had reduced eGFR and had more frequently previous history of cardiovascular complications. The worse cardiovascular risk profile was seen in those patients with both elevated NSBP and abnormal NSD (table). Conclusion: In untreated hypertensive patients an abnormal dipping pattern is more closely related with diabetes and overt cardiovascular and renal disease than nocturnal BP elevation without circadian pattern alterations .